Method and apparatus for steel production



July 26, 1966 I A. G. VANDERBECK 3,262,591

METHOD AND APPARATUS FOR STEEL PRODUCTION Filed Sept. 9, 1963 I I I x I 9. I I l I I I I 2' I I In l I? \IENTOR. ALFRED G. VANDERBECK WWW/M ATTORNEY United States Patent f 3,262,691 METHOD AND APPARATUS FOR STEEL PRODUCTION Afired G. Vanderbeck, 730 Laurel Lane, Colonial Village, Pa. Filed Sept. 9, 1963, Ser. No. 307,698 4 Claims. (Cl. 26635) This invention is concerned with steel making and in particular contemplates an improved method and apparatus by which a metal charge may be processed efficiently for producing desired steel end products.

The invention is directed to processes which use an oxidizing medium, for example, air or oxygen, for removing carbon and other chemical components during a blow period, such as occurs in the Bessemer process and also with the more recent Oxygen processes. According to this invention, the reaction or blow time is controlled in an entirely different manner from the aforementioned processes in that it is accomplished in accordance with or on the basis of weight decrease of a metal charge, whereas the aforementioned processes control the blow time, primarily, on the characteristics of the flame or radiation produced during a blow period.

In carrying out such prior process, the steel industry has depended almost entirely upon the skill and experience of an operator for determining when a blow period should stop. By observation, an experienced operator determines from the appearance of the flame issuing from the mouth of the converter during a blow period the extent of the reactions occurring therein, that is, the extent of removal of carbon and other oxidizible components. Such operator control is highly uncertain and results in uneconomical operations or production of batches which do not conform to the desired standard. Since there is no definite standard of comparison to check on the process to provide for accurate termination of the blow period, the control is based primarily on the experience or recollection of the operator which is, of course, subject to error.

Patent 2,207,309 to Work and Patent 2,354,400 to Percy appreciate the practical difliculties in operator control of such steel making processes and have attempted to improve the operations by the use of photometric equipment, such as photo-cells, spectroscopes, etc., whereby the flame or radiation characteristics existing during a blow period operate such equipment to effect a more accurate control of a blow period.

In its broader aspects the present invention is prefaced on the idea of establishing the actual weight of a metal charge and to determine by calculation or by prior operations the weight decrease of the charge to produce a steel of desired composition and to stop the blow period when the weight of the charge is reduced to this predetermined value. In its more specific aspects the blow period will be terminated when all reducible components are removed excepting a predetermined and desired percentage of carbon. This is possible on the premise that some carbon remains when other impurities are oxidized and before oxidation of the metal occurs. The predetermined carbon remaining may and preferably is that amount desired for an end steel product.

By way of explaining the process feature of the invention, with the chemical composition of a metal charge known from an analysis of the charge, the percentage of oxidizable components, or impurities such as carbon, silicon, manganese, sulphur, phosphorous, etc., may be calculated on a weight basis and their total weight determined. As a blow period proceeds and the weight of the charge is reduced to a predetermined value, it will be terminated by an operator or by suitable automatic controls. In determining the weight of a charge, it is necessary in 3,262,691 Patented July 26, 1966 practicing the invention to known the tare weight of the converter before each operation since the converter weight may and probably will vary from one operation to another due to such factors as erosion of the converter refractory lining and also by metal and other accumulation in the converter. After the tare weight is determined, the gross weight of the converter :and charge are determined and the oxidizing gas supplied to the converter until the gross weight is lowered to the predetermined value which will be known as reduced weight in this application.

The apparatus of the invention requires converter equipment for receiving the charge, weight scales or sensing means operative in accordance with the weight of the converter equipment, an indicator responsive to weight changes to show the converter or tare weight, the gross weight of the converter and charge, and the reduced weight of the converter and charge and means operative to terminate the supply of oxidizing gas to the converter equipment when the reduced weight reaches a predetermined value.

The single figure of the drawing is a diagrammatic representation of an arrangement of converter, weight sensing means, indicator and recording chart for carrying out the invention.

In the drawing, the converter 10 is mounted by a trunnion 11 between standards 12 in a manner to permit the converter to be tilted for pouring in the customary manner. The level of the metal charge is indicated by the broken line at M and the oxidizing gas is supplied to the converter 10 from a source 13 at desired operating pressure, rate, etc. The weight sensing means consisting of a plurality of load cells shown at 14-14 which are strain or force responsive are conveniently mounted on the trunnion 11 and connected by leads 1515' with a junction 16 which is in circuit with an indicator 17 by lead 18. The particular load cell system of cells and indicator may be of the type shown in Bulletin R-Z, 1961, of W. C. Dillon & Co., Inc., Van Nuys, Calif, at photograph 10, for example, which are especially adapted for converter or hopper weighing. A lead 19 is in circuit between the indicator 17 and a controller 20 which operates valve 21 to cut off the supply of oxidizing medium when the reduced weight shown by the indicator 17 reaches the predetermined value. A recorder is placed in circuit with indicator 17 through line 22 and as shown on the recorder chart, 23 represents the tare weight of the converter, line 24 represents the gross weight of the converter and charge and line 25 represents the reduced weight or end of blow weight of the converter and charge. The indicator 17 will show these respective weights as an operation is being carried out while the recorder data may be used for subsequent operations which may be programmed.

The invention lends itself to other refinements in steel making operations which may overcome some of the problems incident thereto. It is well known, for example, that a converter needs repair or replacement after periods of use due to normal wear and particularly due to erosion of the refractory lining of the converter. By the use of the described apparatus the refractory lining of a converter may be replaced when the tare weight, as shown by the recorder is reduced to a predetermined value which is based on prior operations with a similar converter. Additionally, since the weight of the charge may be upwardly of 400,000 pounds, the indicator 17 may be calibrated to show the weights on a percentage basis of total weight.

The following example is provided to show data of one practical operation of the invention. In the example, only the carbon weight is specifically shown and the total weight of the other impurities shown, in the interest of simplicity of explanation.

3 Charge 400,000 Metal 370,600 Carbon 16,800 Other impurities 12,600 Oxidized charge 371,800 Retained carbon 1,200 Other impurities None From the example, it will be understood that a charge of 400,000 pounds has been calculated from its analysis to contain 370,600 pounds of metal, 16,800 pounds of carbon and 12,600 pounds of other impurities. The oxidized charge has been reduced in weight to 371,800 pounds during the blow period of which 1,200 pounds is carbon. The blow period in this example terminated when the weight of the charge was reduced to 371,800 pounds and the 1,200 pounds of carbon Was retained to provide substautially the carbon required for a desired steel product. Other desired components for the steel end product will be added as required.

It Will be understood that modifications of the procedure and apparatus described herein may be resorted to without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Apparatus for preparing a metal charge for the production of steel which comprises converter equipment for containing a metal charge, scale means responsive to the weight of the converter equipment, weight indicating means operative by said scale means, a conduit having a valve therein for supplying an oxidizing medium from a source to the converter equipment and means operative by said weight indicating means to close the valve when the weight of the converter equipment and metal charge therein is reduced to a predetermined value by the oxidizing medium.

2. Apparatus for preparing a metal charge for the production of steel which comprises converter equipment for containing a metal charge, scale means carried by the converter equipment and responsive to its weight, weight indicating means operative by said scale means, a conduit having a valve therein for supplying an oxidizing medium from a source to the converter equipment, means operative by said weight indicating means to close the valve when the weight of the converter and metal charge is reduced to a predetermined value and a recorder operative by the indicating means,

3. Apparatus for preparing a metal charge for the production of steel which comprises converter equipment for containing a metal charge, an electrical Weight indicating system, said system comprising strain or force responsive elements carried by the converter equipment and in circuit with an indicator, a conduit having a valve therein for supplying an oxidizing medium from a source to a metal charge in the converter equipment, a controller operative by said indicator to close the valve when the Weight of the converter and metal charge is reduced to a predetermined value.

4. Apparatus for preparing a metal charge for the production of steel which comprises a converter mounted by support means for containing a metal charge, an electrical weight indicating system, said system comprising load cell means carried by the support means to be responsive to strain or force applied to the support means and in circuit with an indicator, a conduit having a valve therein for supplying an oxidizing medium from a source to a metal charge in the converter equipment, a controller operative by said indicator to close the .valve when the weight of the converter and metal charge is reduced to a predetermined value and a recorder operative by the indicator to show weight changes in a converter during an operation.

References Cited by the Examiner UNITED STATES PATENTS 2,207,309 7/1940 Work 60 2,354,400 7/ 1944 Percy 7560 2,807,537 9/1957 Murphy 7552 BENJAMIN HENKIN, Primary Examiner. 

1. APPARATUS FOR PREPARING A METAL CHARGE FOR THE PRODUCTION OF STEEL WHICH COMPRISES CONVERTER EQUIPMENT FOR CONTAINING A METAL CHARGE, SCALE MEANS RESPONSIVE TO THE WEIGHT OF THE CONVERTER EQUIPMENT, WEIGHT INDICATING MEANS OPERATIVE BY SAID SCALE MEANS, A CONDUIT HAVING A VALVE THEREIN FOR SUPPLYING AN OXIDIZING MEDIUM FROM A SOURCE TO THE CONVERTER EQUIPMENT AND MEANS OPERATIVE 